Carbon dioxide reduction reaction (CO2RR) provides a promising method for syngas synthesis. However, it is challenging to balance the CO2RR activity and hydrogen (H2)/carbon monoxide (CO) ratios due to the limited mass transport and inefficient catalytic interface. Herein, we adopt a nitrogen (N)-modification method to synthesize N-modified nickel antimony nanowires (N-NiSb NWs/C), which are efficient for producing syngas with controllable H2/CO ratios. Significantly, the optimized N-NiSb NWs/C, with boosted electrochemical CO2RR activity, have the flexibility to control H2/CO ratios in syngas from nearly 1 to 4 in a wide potential range. The mechanistic discussion shows that the electronic structure of NiSb NWs/C can be optimized by using the synergistic effect between Ni and Sb, as well as the reasonable surface modification, so that a controllable syngas can be obtained. Our design provides an ideal platform for generating syngas with widely controllable H2/CO ratios.